package com.atguigu.spring5;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;

public class JDKProxy {

    public static void main(String[] args) {
        //创建接口实现类的代理对象
        Class[] interfcer = {UserDao.class};
//        Proxy.newProxyInstance(JDKProxy.class.getClassLoader(), interfcer, new InvocationHandler() {
//            @Override
//            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
//                return null;
//            }
//        });

        UserDaoImpl userDao = new UserDaoImpl();

        UserDao dao = (UserDao) Proxy.newProxyInstance(JDKProxy.class.getClassLoader(), interfcer, new UserDaoProxy(userDao));

        int result = dao.add(1, 2);
        System.out.println("result=" + result);

    }

}

//创建代理对象的代码
class UserDaoProxy implements InvocationHandler {

    //1.把创建的是谁的代理对象，把谁传递过来
    //有参数的构造传递
    //通过object来传递被代理类，更通用

    private Object obj;

    public UserDaoProxy(Object obj) {
        this.obj = obj;
    }


    //增强的逻辑
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

        //方法之前
        System.out.println("方法之前执行......." + method.getName() + ":传递的参数......" + Arrays.toString(args));

        //被增强的方法执行
        Object res = method.invoke(obj, args);

        //方法之后
        System.out.println("方法之后执行......." + obj);

        return res;

    }

}
